Measles, also known as rubeola or morbilli, is a highly infectious illness caused by the rubeola virus.
Measles is an endemic disease, meaning it is continually present in a community and many people develop resistance. However, if measles enters an area where the people have never been exposed, the result can be devastating.
A measles outbreak in 1592 on the island of Cuba killed approximately two-thirds of the native population. A couple of years later, half the indigenous population of Honduras died.
Over the last 150 years, the total global measles death toll is an estimated 200 million people.
This article will explain the cause of measles, its symptoms, treatment, and prevention.
Contents of this article:
Fast facts on measles
Here are some key points about measles. More detail and supporting information is in the main article.
- Measles is a highly infectious condition
- Symptoms of measles can include watery eyes, sneezing, and a dry hacking cough
- It takes 1-3 weeks for the measles virus to establish itself
- There is no specific treatment for measles; prevention is better than cure
- Pregnant women should not take the vaccine
- Scientists have identified 21 strains of the measles virus
Symptoms of measles
Measles symptoms can often include a reddish-brown spotty rash.
Measles is an infection caused by the rubeola virus; its symptoms always include fever and at least one of the three C's - cough, coryza (runny nose), and conjunctivitis. Symptoms will appear about 9-11 days after initial infection.
Measles symptoms may include the following:
- Coryza - runny nose.
- Dry hacking cough.
- Conjunctivitis - swollen eyelids, inflamed eyes.
- Watery eyes.
- Photophobia - sensitivity to light.
- Fever - this may be mild to severe and can reach 40.6 degrees Centigrade for a number of days. Fever may drop and then rise again when the rash appears.
- Koplik's spots - very small grayish-white spots with bluish-white centers in the mouth, insides of cheeks, and throat.
- Generalized body aches.
- Rash - 3 to 4 days after initial symptoms, a reddish-brown spotty rash appears. The rash can last for over a week. It usually starts behind the ears and spreads all over the head and neck. After a couple of days, it spreads to the rest of the body, including the legs. As the little spots grow, many of them will join together.
Although the majority of childhood rashes are not measles, a child should be taken to the doctors if:
- A parent suspects it could be measles
- Symptoms do not improve, or get worse
- The fever rises to above 38 degrees Centigrade
- When other symptoms have resolved except for fever
Cause of measles
Measles is caused by infection with the rubeola virus. The virus lives in the mucus of the nose and throat of an infected child or adult. The infected person is contagious for 4 days before the rash appears and continues so for about 4-5 days afterward.
Infection can arise through:
- Physical contact with an infected person
- Being nearby infected people if they cough or sneeze
- Touching a surface that has infected droplets of mucus (the virus remains active for 2 hours) and then putting fingers into the mouth, or rubbing the nose or eyes
How does a measles infection develop?
As soon as the virus enters the body, it multiplies in the back of the throat, lungs, and the lymphatic system. It later infects and replicates in the urinary tract, eyes, blood vessels, and central nervous system.
Experts say it takes 1-3 weeks for the virus to establish itself. However, people show symptoms 9-11 days after acquiring the infection.
A person who has had measles before does not become infected again; cases of re-infection are very rare. However, anyone who has never been infected or vaccinated that breathes in infected droplets or is in close physical contact with an infected person is likely to become ill.
Approximately 90 percent of people who are not immune will develop measles if they share a house with an infected person.
A doctor will be able to diagnose measles fairly easily if the signs and symptoms are present. A blood test will confirm the presence of the rubeola virus.
In most countries, measles is a notifiable disease. This means that doctors have to notify the authorities of any suspected cases. If the patient is a child, the doctor will also notify the school.
A child with measles should not return to school until at least 5 days after the rash has appeared.
Treatments for measles
There is no specific measles treatment. If there are no complications, the doctor will recommend plenty of rest and normal measures to control the fever and prevent dehydration (drink fluids). Symptoms will usually go away within 7-10 days.
If a child has measles, the following measures may help:
- Fever - if the temperature is high, the child should be kept cool, but not too cold. Tylenol (paracetamol, acetaminophen) or ibuprofen are effective in controlling fever, as well as aches and pain. Children under 16 should not be given aspirin. Check with a doctor about acetaminophen dosage - too much can harm the child, especially the liver.
- Smoking - do not smoke near the child.
- Photophobia - as the child may be sensitive to light, keeping the lights dim or the room darkened may help. Sunglasses may also help.
- Conjunctivitis - if there is crustiness around the eyes, gently clean with a warm, damp cloth.
- Cough - cough medicines will not relieve the cough. Humidifiers or placing a bowl of water in the room may help. If the child is over 12, a glass of warm water with a teaspoon of lemon juice and two teaspoons of honey may help. Do not give honey to infants.
- Dehydration - make sure the child is hydrated. If the child has a fever, they can become dehydrated more quickly. Encourage the child to drink plenty of fluids.
- Isolation - during the contagious stage, infected children should be kept away from school and should not return to activities that involve human interaction. Non-immunized people who have never had measles should be kept out of the house.
- Vitamin A supplements - studies have shown that vitamin A supplements significantly help prevent complications caused by measles. Supplements are recommended for children with vitamin A deficiency and children under the age of 2 who have severe measles. Vitamin A deficiency is virtually non-existent in developed countries, but fairly common in much of the developing world.
As measles is caused by a virus, antibiotics will not have any effect on it. However, antibiotics may sometimes be prescribed for any additional bacterial infections that develop.
Complications of measles
Vomiting is a common complication of measles.
Complications from measles are fairly common and are more likely to be worse for patients who have weak immune systems, such as those with HIV/AIDS or leukemia, those with vitamin deficiency, and very young children.
Adults over the age of 20 are more likely to have complications than healthy children over the age of 5.
Complications can include:
- Eye infection.
- Laryngitis and bronchitis - laryngitis is inflammation of the voice box; bronchitis is inflammation of the inner walls of airways. About 4 percent of people with measles have difficulties breathing.
- Otitis media - inner ear infection and inflammation.
- Febrile seizure - Occurs in 1 in 200 cases. They may be alarming, but children usually make a full recovery.
- Pneumonia - patients with a weakened immune system who develop measles are vulnerable to developing bacterial pneumonia (Streptococcus pneumoniae), which can be fatal if not treated.
The following less common complications are also possible:
- Hepatitis - liver complications in childhood measles are rare and temporary. However, it can be severe in children receiving hepatotoxic drugs (medications which may be toxic to the liver). Acetaminophen (Tylenol, paracetamol) can harm the liver if the dose is too high.
- Encephalitis - approximately 1 in every 1,000 patients with measles develops encephalitis. This is an inflammation of the brain which can cause vomiting and convulsions. Coma and even death is possible but rare. Encephalitis may occur soon after measles, or several years later.
- Thrombocytopenia - low platelet count. The blood's ability to clot is affected. The patient may bruise easily.
- Squint - eye nerves and eye muscles may be affected.
The complications listed below are very rare, but possible:
- Neuritis - infection of the optic nerve, which can lead to blindness.
- Heart complications.
- Subacute sclerosing panencephalitis (SSPE) - Occurs in 2 in every 100,000 cases. SSPE is a brain disease which can occur months or years after measles infection and causes convulsions, motor abnormalities, mental retardation, and death.
- Other nervous system complications - toxic encephalopathy, retrobulbar neuritis, transverse myelitis, and ascending myelitis.
Measles during pregnancy can cause miscarriage, premature labor, or low birth weights. If an individual is planning on getting pregnant and has not been vaccinated against measles, they should speak with their doctor.
Prevention of measles
People who have already had measles are immune and will not get it again - cases of re-infection are extremely rare. Experts say that, if you were born or living in the United States before 1957, you will be immune.
For people who are not immune, there is the measles vaccine.
The World Health Organization (WHO) says that nearly 600 million children received the measles vaccine between 2000 and 2007, resulting in a 74 percent drop in global deaths caused by measles - and a drop of about 90 percent in the eastern Mediterranean and Africa regions.
Autism concerns and the MMR vaccine
In many countries, concern grew about an alleged link between the MMR vaccine and autism risk - caused by mercury (thimerosal) in the vaccines. Several extensive studies from North America, United Kingdom, France, Germany, Scandinavia, and Japan have found no evidence of a link. Scientists and virtually all doctors believe the risk does not exist - this includes hundreds of thousands of scientists and doctors worldwide who have no vested interest in the outcome of those studies.
When should children be vaccinated?
Children should receive the MMR (Mumps, Measles, Rubella) vaccine when they are between 12 and 15 months of age, and then again (a booster) before entering school when they are 4-6 years old. Babies carry their mother's immunity for a few months after birth if their mothers are immune.
Sometimes babies require vaccination before they are 12 months old. This may happen if there is a serious outbreak in their area, or if they are going to travel to an area with a serious outbreak. In such cases, they can receive the vaccination from the age of 6 months and will need a booster when they are 12 months old.
Adults do not require a vaccine in the U.S. if:
- They were born before 1957 in the U.S., or lived there before 1957
- Received two MMR shots after they were 12 months old
- Had one MMR vaccine plus a second dose of measles vaccine
- Are found to be immune to measles, mumps, and rubella after a blood test
The vaccine should not be taken by:
- Pregnant women
- Women who plan to become pregnant very soon (check with a doctor)
- People who are seriously allergic to gelatin or neomycin (antibiotic)
Anybody who has a condition or disease that affects their immune system, as well as people receiving treatment which weakens their immune system should ask their doctor whether they should receive the vaccine.